/*
 *  FIPS-180-2 compliant SHA-256 implementation
 *
 *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
 *  SPDX-License-Identifier: GPL-2.0
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 *  This file is part of mbed TLS (https://tls.mbed.org)
 */
/*
 *  The SHA-256 Secure Hash Standard was published by NIST in 2002.
 *
 *  http://csrc.nist.gov/publications/fips/fips180-2/fips180-2.pdf
 */

#include "sha256.h"
#include "utils.h"

#include <string.h>

#if defined(MBEDTLS_SELF_TEST)
#if defined(MBEDTLS_PLATFORM_C)
#include "mbedtls/platform.h"
#else
#include <stdio.h>
#include <stdlib.h>
#define mbedtls_printf printf
#define mbedtls_calloc calloc
#define mbedtls_free free
#endif /* MBEDTLS_PLATFORM_C */
#endif /* MBEDTLS_SELF_TEST */

#define SHA256_VALIDATE_RET(cond)
#define SHA256_VALIDATE(cond)

#if !defined(MBEDTLS_SHA256_ALT)

/*
 * 32-bit integer manipulation macros (big endian)
 */
#ifndef GET_UINT32_BE
#define GET_UINT32_BE(n, b, i)                                                                                                                                                            \
	do                                                                                                                                                                                    \
	{                                                                                                                                                                                     \
		(n) = (static_cast<uint32_t>((b)[(i)]) << 24) | (static_cast<uint32_t>((b)[(i) + 1]) << 16) | (static_cast<uint32_t>((b)[(i) + 2]) << 8) | (static_cast<uint32_t>((b)[(i) + 3])); \
	} while (0)
#endif

#ifndef PUT_UINT32_BE
#define PUT_UINT32_BE(n, b, i)                                \
	do                                                        \
	{                                                         \
		(b)[(i)] = static_cast<unsigned char>((n) >> 24);     \
		(b)[(i) + 1] = static_cast<unsigned char>((n) >> 16); \
		(b)[(i) + 2] = static_cast<unsigned char>((n) >> 8);  \
		(b)[(i) + 3] = static_cast<unsigned char>((n));       \
	} while (0)
#endif

void mbedtls_sha256_init(mbedtls_sha256_context* ctx)
{
	SHA256_VALIDATE(ctx != NULL);

	memset(ctx, 0, sizeof(mbedtls_sha256_context));
}

void mbedtls_sha256_free(mbedtls_sha256_context* ctx)
{
	if (ctx == NULL)
		return;

	mbedtls_zeroize(ctx, sizeof(mbedtls_sha256_context));
}

void mbedtls_sha256_clone(mbedtls_sha256_context* dst,
	const mbedtls_sha256_context* src)
{
	SHA256_VALIDATE(dst != NULL);
	SHA256_VALIDATE(src != NULL);

	*dst = *src;
}

/*
 * SHA-256 context setup
 */
int mbedtls_sha256_starts_ret(mbedtls_sha256_context* ctx, int is224)
{
	SHA256_VALIDATE_RET(ctx != NULL);
	SHA256_VALIDATE_RET(is224 == 0 || is224 == 1);

	ctx->total[0] = 0;
	ctx->total[1] = 0;

	if (is224 == 0)
	{
		/* SHA-256 */
		ctx->state[0] = 0x6A09E667;
		ctx->state[1] = 0xBB67AE85;
		ctx->state[2] = 0x3C6EF372;
		ctx->state[3] = 0xA54FF53A;
		ctx->state[4] = 0x510E527F;
		ctx->state[5] = 0x9B05688C;
		ctx->state[6] = 0x1F83D9AB;
		ctx->state[7] = 0x5BE0CD19;
	}
	else
	{
		/* SHA-224 */
		ctx->state[0] = 0xC1059ED8;
		ctx->state[1] = 0x367CD507;
		ctx->state[2] = 0x3070DD17;
		ctx->state[3] = 0xF70E5939;
		ctx->state[4] = 0xFFC00B31;
		ctx->state[5] = 0x68581511;
		ctx->state[6] = 0x64F98FA7;
		ctx->state[7] = 0xBEFA4FA4;
	}

	ctx->is224 = is224;

	return (0);
}

#if !defined(MBEDTLS_DEPRECATED_REMOVED)
void mbedtls_sha256_starts(mbedtls_sha256_context* ctx,
	int is224)
{
	mbedtls_sha256_starts_ret(ctx, is224);
}
#endif

#if !defined(MBEDTLS_SHA256_PROCESS_ALT)
static const uint32_t K[] =
	{
		0x428A2F98,
		0x71374491,
		0xB5C0FBCF,
		0xE9B5DBA5,
		0x3956C25B,
		0x59F111F1,
		0x923F82A4,
		0xAB1C5ED5,
		0xD807AA98,
		0x12835B01,
		0x243185BE,
		0x550C7DC3,
		0x72BE5D74,
		0x80DEB1FE,
		0x9BDC06A7,
		0xC19BF174,
		0xE49B69C1,
		0xEFBE4786,
		0x0FC19DC6,
		0x240CA1CC,
		0x2DE92C6F,
		0x4A7484AA,
		0x5CB0A9DC,
		0x76F988DA,
		0x983E5152,
		0xA831C66D,
		0xB00327C8,
		0xBF597FC7,
		0xC6E00BF3,
		0xD5A79147,
		0x06CA6351,
		0x14292967,
		0x27B70A85,
		0x2E1B2138,
		0x4D2C6DFC,
		0x53380D13,
		0x650A7354,
		0x766A0ABB,
		0x81C2C92E,
		0x92722C85,
		0xA2BFE8A1,
		0xA81A664B,
		0xC24B8B70,
		0xC76C51A3,
		0xD192E819,
		0xD6990624,
		0xF40E3585,
		0x106AA070,
		0x19A4C116,
		0x1E376C08,
		0x2748774C,
		0x34B0BCB5,
		0x391C0CB3,
		0x4ED8AA4A,
		0x5B9CCA4F,
		0x682E6FF3,
		0x748F82EE,
		0x78A5636F,
		0x84C87814,
		0x8CC70208,
		0x90BEFFFA,
		0xA4506CEB,
		0xBEF9A3F7,
		0xC67178F2,
};

#define SHR(x, n) (((x) & 0xFFFFFFFF) >> (n))
#define ROTR(x, n) (SHR(x, n) | ((x) << (32 - (n))))

#define S0(x) (ROTR(x, 7) ^ ROTR(x, 18) ^ SHR(x, 3))
#define S1(x) (ROTR(x, 17) ^ ROTR(x, 19) ^ SHR(x, 10))

#define S2(x) (ROTR(x, 2) ^ ROTR(x, 13) ^ ROTR(x, 22))
#define S3(x) (ROTR(x, 6) ^ ROTR(x, 11) ^ ROTR(x, 25))

#define F0(x, y, z) (((x) & (y)) | ((z) & ((x) | (y))))
#define F1(x, y, z) ((z) ^ ((x) & ((y) ^ (z))))

#define R(t)                                 \
	(                                        \
		W[t] = S1(W[(t) - 2]) + W[(t) - 7] + \
	           S0(W[(t) - 15]) + W[(t) - 16])

#define P(a, b, c, d, e, f, g, h, x, K)                      \
	do                                                       \
	{                                                        \
		temp1 = (h) + S3(e) + F1((e), (f), (g)) + (K) + (x); \
		temp2 = S2(a) + F0((a), (b), (c));                   \
		(d) += temp1;                                        \
		(h) = temp1 + temp2;                                 \
	} while (0)

int mbedtls_internal_sha256_process(mbedtls_sha256_context* ctx,
	const unsigned char data[64])
{
	uint32_t temp1, temp2, W[64];
	uint32_t A[8];
	unsigned int i;

	SHA256_VALIDATE_RET(ctx != NULL);
	SHA256_VALIDATE_RET((const unsigned char*)data != NULL);

	for (i = 0; i < 8; i++)
		A[i] = ctx->state[i];

#if defined(MBEDTLS_SHA256_SMALLER)
	for (i = 0; i < 64; i++)
	{
		if (i < 16)
			GET_UINT32_BE(W[i], data, 4 * i);
		else
			R(i);

		P(A[0], A[1], A[2], A[3], A[4], A[5], A[6], A[7], W[i], K[i]);

		temp1 = A[7];
		A[7] = A[6];
		A[6] = A[5];
		A[5] = A[4];
		A[4] = A[3];
		A[3] = A[2];
		A[2] = A[1];
		A[1] = A[0];
		A[0] = temp1;
	}
#else  /* MBEDTLS_SHA256_SMALLER */
	for (i = 0; i < 16; i++)
		GET_UINT32_BE(W[i], data, 4 * i);

	for (i = 0; i < 16; i += 8)
	{
		P(A[0], A[1], A[2], A[3], A[4], A[5], A[6], A[7], W[i + 0], K[i + 0]);
		P(A[7], A[0], A[1], A[2], A[3], A[4], A[5], A[6], W[i + 1], K[i + 1]);
		P(A[6], A[7], A[0], A[1], A[2], A[3], A[4], A[5], W[i + 2], K[i + 2]);
		P(A[5], A[6], A[7], A[0], A[1], A[2], A[3], A[4], W[i + 3], K[i + 3]);
		P(A[4], A[5], A[6], A[7], A[0], A[1], A[2], A[3], W[i + 4], K[i + 4]);
		P(A[3], A[4], A[5], A[6], A[7], A[0], A[1], A[2], W[i + 5], K[i + 5]);
		P(A[2], A[3], A[4], A[5], A[6], A[7], A[0], A[1], W[i + 6], K[i + 6]);
		P(A[1], A[2], A[3], A[4], A[5], A[6], A[7], A[0], W[i + 7], K[i + 7]);
	}

	for (i = 16; i < 64; i += 8)
	{
		P(A[0], A[1], A[2], A[3], A[4], A[5], A[6], A[7], R(i + 0), K[i + 0]);
		P(A[7], A[0], A[1], A[2], A[3], A[4], A[5], A[6], R(i + 1), K[i + 1]);
		P(A[6], A[7], A[0], A[1], A[2], A[3], A[4], A[5], R(i + 2), K[i + 2]);
		P(A[5], A[6], A[7], A[0], A[1], A[2], A[3], A[4], R(i + 3), K[i + 3]);
		P(A[4], A[5], A[6], A[7], A[0], A[1], A[2], A[3], R(i + 4), K[i + 4]);
		P(A[3], A[4], A[5], A[6], A[7], A[0], A[1], A[2], R(i + 5), K[i + 5]);
		P(A[2], A[3], A[4], A[5], A[6], A[7], A[0], A[1], R(i + 6), K[i + 6]);
		P(A[1], A[2], A[3], A[4], A[5], A[6], A[7], A[0], R(i + 7), K[i + 7]);
	}
#endif /* MBEDTLS_SHA256_SMALLER */

	for (i = 0; i < 8; i++)
		ctx->state[i] += A[i];

	return (0);
}

#if !defined(MBEDTLS_DEPRECATED_REMOVED)
void mbedtls_sha256_process(mbedtls_sha256_context* ctx,
	const unsigned char data[64])
{
	mbedtls_internal_sha256_process(ctx, data);
}
#endif
#endif /* !MBEDTLS_SHA256_PROCESS_ALT */

/*
 * SHA-256 process buffer
 */
int mbedtls_sha256_update_ret(mbedtls_sha256_context* ctx,
	const unsigned char* input,
	size_t ilen)
{
	int ret;
	size_t fill;
	uint32_t left;

	SHA256_VALIDATE_RET(ctx != NULL);
	SHA256_VALIDATE_RET(ilen == 0 || input != NULL);

	if (ilen == 0)
		return (0);

	left = ctx->total[0] & 0x3F;
	fill = 64 - left;

	ctx->total[0] += static_cast<uint32_t>(ilen);
	ctx->total[0] &= 0xFFFFFFFF;

	if (ctx->total[0] < static_cast<uint32_t>(ilen))
		ctx->total[1]++;

	if (left && ilen >= fill)
	{
		memcpy(ctx->buffer + left, input, fill);

		if ((ret = mbedtls_internal_sha256_process(ctx, ctx->buffer)) != 0)
			return (ret);

		input += fill;
		ilen -= fill;
		left = 0;
	}

	while (ilen >= 64)
	{
		if ((ret = mbedtls_internal_sha256_process(ctx, input)) != 0)
			return (ret);

		input += 64;
		ilen -= 64;
	}

	if (ilen > 0)
		memcpy(ctx->buffer + left, input, ilen);

	return (0);
}

#if !defined(MBEDTLS_DEPRECATED_REMOVED)
void mbedtls_sha256_update(mbedtls_sha256_context* ctx,
	const unsigned char* input,
	size_t ilen)
{
	mbedtls_sha256_update_ret(ctx, input, ilen);
}
#endif

/*
 * SHA-256 final digest
 */
int mbedtls_sha256_finish_ret(mbedtls_sha256_context* ctx,
	unsigned char output[32])
{
	int ret;
	uint32_t used;
	uint32_t high, low;

	SHA256_VALIDATE_RET(ctx != NULL);
	SHA256_VALIDATE_RET((unsigned char*)output != NULL);

	/*
	 * Add padding: 0x80 then 0x00 until 8 bytes remain for the length
	 */
	used = ctx->total[0] & 0x3F;

	ctx->buffer[used++] = 0x80;

	if (used <= 56)
	{
		/* Enough room for padding + length in current block */
		memset(ctx->buffer + used, 0, 56 - used);
	}
	else
	{
		/* We'll need an extra block */
		memset(ctx->buffer + used, 0, 64 - used);

		if ((ret = mbedtls_internal_sha256_process(ctx, ctx->buffer)) != 0)
			return (ret);

		memset(ctx->buffer, 0, 56);
	}

	/*
	 * Add message length
	 */
	high = (ctx->total[0] >> 29) | (ctx->total[1] << 3);
	low = (ctx->total[0] << 3);

	PUT_UINT32_BE(high, ctx->buffer, 56);
	PUT_UINT32_BE(low, ctx->buffer, 60);

	if ((ret = mbedtls_internal_sha256_process(ctx, ctx->buffer)) != 0)
		return (ret);

	/*
	 * Output final state
	 */
	PUT_UINT32_BE(ctx->state[0], output, 0);
	PUT_UINT32_BE(ctx->state[1], output, 4);
	PUT_UINT32_BE(ctx->state[2], output, 8);
	PUT_UINT32_BE(ctx->state[3], output, 12);
	PUT_UINT32_BE(ctx->state[4], output, 16);
	PUT_UINT32_BE(ctx->state[5], output, 20);
	PUT_UINT32_BE(ctx->state[6], output, 24);

	if (ctx->is224 == 0)
		PUT_UINT32_BE(ctx->state[7], output, 28);

	return (0);
}

#if !defined(MBEDTLS_DEPRECATED_REMOVED)
void mbedtls_sha256_finish(mbedtls_sha256_context* ctx,
	unsigned char output[32])
{
	mbedtls_sha256_finish_ret(ctx, output);
}
#endif

#endif /* !MBEDTLS_SHA256_ALT */

/*
 * output = SHA-256( input buffer )
 */
int mbedtls_sha256_ret(const unsigned char* input,
	size_t ilen,
	unsigned char output[32],
	int is224)
{
	int ret;
	mbedtls_sha256_context ctx;

	SHA256_VALIDATE_RET(is224 == 0 || is224 == 1);
	SHA256_VALIDATE_RET(ilen == 0 || input != NULL);
	SHA256_VALIDATE_RET((unsigned char*)output != NULL);

	mbedtls_sha256_init(&ctx);

	if ((ret = mbedtls_sha256_starts_ret(&ctx, is224)) != 0)
		goto exit;

	if ((ret = mbedtls_sha256_update_ret(&ctx, input, ilen)) != 0)
		goto exit;

	if ((ret = mbedtls_sha256_finish_ret(&ctx, output)) != 0)
		goto exit;

exit:
	mbedtls_sha256_free(&ctx);

	return (ret);
}

#if !defined(MBEDTLS_DEPRECATED_REMOVED)
void mbedtls_sha256(const unsigned char* input,
	size_t ilen,
	unsigned char output[32],
	int is224)
{
	mbedtls_sha256_ret(input, ilen, output, is224);
}
#endif
